(Trichloromethyl)pyridine compounds, such as nitrapyrin (2-chloro-6-(trichloromethyl)pyridine), inhibit the process of nitrification and have been or are currently used in combination with nitrogen based fertilizers as described in U.S. Pat. No. 3,135,594, which is herein incorporated by reference. The application of these compounds helps to maintain levels of ammonium nitrogen applied to the soil in the ammonium form (plant accessible stabilized nitrogen); higher levels of plant accessible nitrogen in the soil enhances crop performance and can increase crop yields.
Due to their volatile nature some formulations of nitrapyrin, also referred to herein as liquid inhibitior compositions, are best applied by incorporating them mechanically into the soil, or by watering them into the soil within about 8 hours after applying them to the surface of the soil. Some encapsulated formulations of nitrapyrin are suitable for rapid or dump release of nitrapyrin into the soil. Some formulations of nitrapyrin encapsulated with lignin sulfonates, especially useful for quick release applications, are disclosed in U.S. Pat. No. 4,746,513, which is incorporated herein by reference. Polycondensation encapsulation, as disclosed in U.S. Pat. No. 5,925,464, has also been used to encapsulate agriculturally active ingredients such as nitrapyrin, particularly to enhance handling safety and storage stability of the active ingredient by using polyurethane rather than polyurea encapsulants.
Encapsulated nitrapyrin formulations exhibit certain advantages over liquid non-encapsulated formulations of nitrapyrin, such as improved stability. Despite the advantages of encapsulated nitrapyrin formulations, liquid non-encapsulated formulations of nitrapyrin are still used, at least in part, because they tend to be easier to formulate and may cost less than encapsulated nitrapyrin formulations. As with most any soil amendment there is an advantage to using formulations that include a high level of the agriculturally active component of the formulation. Formulations that have higher levels of an active ingredient generally mean that less material must be moved, stored, and applied to the field; the net result is that these formulations may exhibit lower material handling costs.
In most commercially available liquid formulations the level of nitrapyrin has been limited by the need to pair nitrapyrin with relatively non-corrosive solvents. Some aspects of the present invention provide a liquid formulation of nitrapyrin (i.e., a liquid inhibitor composition) that includes a relatively high level of nitrapyrin. In these inventive formulations nitrapyrin is present in polar solvents and is especially formulated to be non-corrosive or at least less corrosive than previous formulations of nitrapyrin that included significant levels of polar solvents. Dibasic ester, as used herein, refers to a compound containing two ester groups. Examples of dibasic esters include, but are not limited to, dimethyl glutarate, dimethyl succinate, dimethyl adipate, dimethyl 2-methylglutarate, and mixtures thereof.
Some embodiments include a liquid formulation of nitrapyrin comprising of: nitrapyrin, at least one polar solvent selected from the group consisting of: (1) N,N-dialkyl fatty acid amides such as those found in products such as, but not limited to, di-substituted amides including for example N,N-di-methyloctanamide (N,N-dimethylcarprylamide) and N,N-dimethyldecanamide (N,N-dimethylcapramide), compounds sold under the trade names, Hallcomid M810, Hallcomid M10, still other compounds that can be used in capacity include, for example, Rhodiasolv® ADMA 810, Rhodiasolv® ADMA 10, Genagen 4166 and Genagen 4296; (2) cyclohexanone; (3) dibasic esters such as, but not limited to, dimethyl 2-methylglutarate, which is available as Rhodiasolv® IRIS, and a dibasic ester mixture composed of dimethyl glutarate, dimethyl succinate, and dimethyl adipate which is available as Rhodiasolv® RPDE; (4) glycol ethers and polyalkylene diglycol ethers such as, but not limited to, dipropylene glycol methyl ether which is available as Dowanol™ DPM; (5) alkylene carbonates such as, but not limited to, propylene carbonate which is available as Jeffsol AG 1555; (6) methyl-5-(dimethylamino)-2-methyl-5-oxopentanoate which is available as Rhodiasolv® Polarclean; (7) organophosphate compounds such as, but not limited to, trialkyl phosphates, (8) alkoxybenzene compounds such as, but not limited to, methoxybenzene (anisole) and ethoxybenzene, (9) ketones such as, but not limited to, cyclopentanone and cyclohexanone, and at least one inhibitor of metal corrosion. The liquid formulations of the present invention may include high levels of nitrapyrin and exhibit relatively non-corrosive properties, making them suitable for use with metal objects such as metal storage tanks and metal application equipment.
In one embodiment, the corrosion inhibitor is selected from the group consisting of: nicotinamide, a picoline, 2,6 lutidine, expoxidized linseed oil (ELO) and DER 331 liquid epoxy resin.
In one embodiment, the corrosion inhibitor is niacin, also known as nicotinic acid. In another embodiment, the corrosion inhibitor is a niacin-derivative. In yet another embodiment, the corrosion inhibitor is niacinamide (it is understood that the terms “niacinamide” and “nicotinamide” are synonymous), methyl isonicotinate, niacin esters, acipimox, aluminum nicotinate, niceritrol, nicoclonate, nicomol, inositol hexaniacinate, oxiniacic acid or combinations thereof.
Non-limiting examples of niacin derivatives include methyl isonicotinate, niacin esters, niacinamide salicylate, niacinamide ascorbate, niacinamide folate, niacinamide lipoate, niacinamide lactate, niacinamide glycolate, niacinamide mandalate, niacinamide malate, niacinamide hydroxycitrate, niacinamide hydroxytetronate, niacinamide aleurate, niacinamide petroselinate, niacinamide pantothenate, niacinamide adenosine monophosphate (AMP), niacinamide diphosphate (ADP), niacinamide adenosine triphosphate (ATP), niacinamide hydroquinone carboxylate, nicotinic acid, niacinamide, Acipimox (5-methylpyrazinecarboxylic acid, 4-oxide), aluminum nicotinate, Niceritrol (3-pyridinecarboxylic acid 2,2-bis [[3-pyridinylcarbonyl]oxy]methyl)-1,3-propanediyl ester, Nicoclonate, Nicomol (2,2,6,6-(1-hydroxycyclohexyl) tetramethyltetrakis (3-pyridinecarboxylate), inositol hexaniacinate, and Oxiniacic Acid (3-pyridinecarboxylic acid, 1-oxide.
In another embodiment, the corrosion inhibitor is derivatized linseed oil, including, but not limited to, epoxidized linseed oil. In another embodiment, the corrosion inhibitor is 1,2-epoxydecane. In another embodiment, the corrosion is an amino alcohol, for example, 2-amino-2-methyl-1-propanol (i.e., AMP-95 or AMP-99). In another embodiment, the corrosion inhibitor is an imidazole compound, for example, 1-methyl imidazole. In another embodiment, the polar solvent is diethylene glycol butyl ether (DGBE). In another embodiment, the corrosion inhibitor and/or co-solvent is an esteramide compound.
In yet another embodiment, the corrosion inhibitor is selected from niacinamide, methyl isonicotinate, niacin esters, acipimox, aluminum nicotinate, niceritrol, nicoclonate, nicomol, inositol hexaniacinate, oxiniacic acid, linseed oil or derivatized linseed oil, including but not limited to epoxidized linseed oil, 1,2-epoxydecane, an amino alcohol, for example, 2-amino-2-methyl-1-propanol, 1-methyl imidazole, a quinolone compound such as quinaldine, or any combination thereof.
In another aspect, described herein are liquid fertilizer compositions for use in agricultural applications comprising: one more nitrogenous fertilizer compounds; at least one nitrification inhibitor comprising a (trichloromethyl)pyridine compound; a polar solvent; and, optionally, a corrosion inhibitor.
In one embodiment, the liquid inhibitor composition or liquid fertilizer composition further comprises at least one additional component including, but not limited to, a co-solvent, a pH adjustor, flow agents, preservatives, buffering agents, antifoam agents, compatibility agents, deposition agents, dispersants, drift control agents, penetrants, surfactants, spreaders, and wetting agents, and the like. In one embodiment, the nitrogenous fertilizer compound is anhydrous ammonia.
Polar solvents that can be used to practice some embodiment of the invention include, but are not limited to, cyclohexanone, propylene carbonate, N,N-dialkyl fatty acid amides: specifically the mixture of C8/C10 fatty acid N,N-dimethylamides (Hallcomid M810), other fatty acid amides also C8 & C10 N,N-dimethylamides individually, the dibasic ester mixture composed of dimethyl glutarate, dimethyl succinate, and dimethyl adipate, which is available as Rhodiasolv® RPDE, organophosphate compounds which are trialkyl phosphates, and alkoxybenzene compounds such as methoxybenzene (anisole) and ethoxybenzene. In one embodiment, the organophosphate compound may be selected from the group including triethyl phosphate, tri(isobutyl)phosphate, tributoxyethyl phosphate (TBEP) and tris(2-ethylhexyl) phosphate. In one embodiment, the polar solvent is comprised of the dibasic ester mixture composed of dimethyl glutarate, dimethyl succinate, and dimethyl adipate (Rhodiasolv® RPDE) and cyclohexanone. In one embodiment, the alkoxybenzene compound is methoxybenzene (anisole). In one embodiment, the organophosphate compound is triethyl phosphate.
Polar solvents that have not worked in some of the exemplary formulation disclosed herein include; (1) dipropylene glycol monomethyl ether (Dowanol DPM), (2) methyl-5-(dimethylamino)-2-methyl-5-oxopentanoate (Polarclean), solvent mixture composed of reaction mass of dimethyl glutarate, dimethyl succinate, and dimethyl adipate (Rhodiasolv® RPDE), and N-butylpyrrolidone (TamiSolve NxG).
Corrosion inhibitors that may not be well suited, or even efficacious, for the practice of the instant invention include, methyltrioctyl ammonium chloride, poly(12-hydroxyoctadecanoic acid-co-ethylenimine) (e.g., Atlox LP6).
Corrosion inhibitors that may be used to practice some embodiments of the invention include, for example, pyridinecarboxamides (i.e., nicotinamide or niacinamide), methylpyridines (i.e., α-picoline, 2,6 lutidine), epoxidized seed or vegetable oils (i.e., epoxidized linseed oil (ELO), epoxidized soybean oil, etc.) and epoxy resin (liquid reaction product of epichlorohydrin and bisphenol, such as, D.E.R.™ 331™ liquid epoxy resin (DER 331)).
Molecules of the following formulas reduce and/or protect against metal corrosion caused by certain nitrification inhibitors including those disclosed herein, these molecules include:
(1) methylpyridines:

(2) pyridine carboxamides:

(3) pyridine carboxylic acid and esters:

(4) epoxidized seed or vegetable oils:

wherein R1, R2, and R3 independently represent C14-C20 alkyl groups substituted with from zero to four epoxide groups;
(5) an epoxy resin based on bisphenol-type chemistry:
                wherein R1 and R2 independently represent H, C1-C4 alkyl, or phenyl, and R3 and R4 independently represent H, C1-C4 alkyl, C1-C4 haloalkyl, or phenyl;        
(6) 1,2-epoxyalkanes:

(7) 1-alkylimidazoles:

(8) amine salts of nicotinic acid:

wherein R1, R2 and R3 independently represent H, (C1-C18) alkyl or (C1-C18) alkyl substituted with one or more substituents selected from, but not limited to, halogen, hydroxy, alkoxy or alkylthio, provided that the substituents are sterically compatible and the rules of chemical bonding and strain energy are satisfied, or any two of R1, R2 and R3 represent —(CH2)n— where n is an integer from 3-5.
(9) primary, secondary & tertiary amines:

wherein R1, R2 and R3 independently represent H, (C1-C18) alkyl or (C1-C18) alkyl substituted with one or more substituents selected from, but not limited to, halogen, hydroxy, alkoxy or alkylthio, provided that the substituents are sterically compatible and the rules of chemical bonding and strain energy are satisfied, or any two of R1, R2 and R3 represent —(CH2)n— where n is an integer from 3-5;
(10) tertiary amine oxides:

wherein R4, R5 and R6 independently represent (C1-C18) alkyl or (C1-C18) alkyl substituted with one or more substituents selected from, but not limited to, halogen, hydroxy, alkoxy or alkylthio, provided that the substituents are sterically compatible and the rules of chemical bonding and strain energy are satisfied, or any two of R1, R2 and R3 represent —(CH2)n— where n is an integer from 3-5, or
wherein R4 is a straight or branched chain (C1-C18) alkyl or an alkyletherpropyl or alkylamidopropyl of the formula:
                wherein R7 is a straight or branched chain (C10-C18) alkyl, and        
R5 and R6 independently are straight or branched chain (C1-C18) alkyl or ethoxylates or propoxylates of the formula:

wherein n is an integer from 1 to 20;
(11) tetra-substituted ammonium salts:

wherein R1, R2 and R3 independently represents (C1-C16) alkyl or (C1-C18) alkyl substituted with one or more substituents selected from, but not limited to, halogen, hydroxy, alkoxy or alkylthio, provided that the substituents are sterically compatible and the rules of chemical bonding and strain energy are satisfied, or any two of R1, R2 and R3 represent —(CH2)n— where n is an integer from 3-5, R4 represents ((C1-C16) alkyl or arylalkyl), and X− is selected from, but not limited to, chloride, bromide, or iodide;
and mixtures thereof.
A first set of embodiments includes a composition comprising an inhibitor of nitrification; at least one polar solvent miscible corrosion inhibitor; a first solvent, wherein said first solvent is a polar solvent which readily dissolves the nitrification inhibitor; and an optional second solvent, the optional second solvent is miscible in the first solvent and wherein the second solvent is no more polar than the first solvent, in some of these embodiments the inhibitor of nitrification is a (trichloromethyl) pyridine compound such as nitrapyrin (2-chloro-6-(trichloromethyl)pyridine.
A second set of embodiments is provided according to the first set of embodiments wherein the at least one polar solvent miscible corrosion inhibitor is selected from the group consisting of:
(1) methylpyridines:

(2) pyridine carboxamides:

(e.g., nicotinamide and isomers thereof)
(3) pyridine carboxylic acid and esters:

(e.g., nicotinic acid, nicotinate esters, and isomers thereof)
(4) epoxidized seed or vegetable oils:

wherein R1, R2, and R3 independently represent C14-C20 alkyl groups substituted with from zero to four epoxide groups.
(5) epoxy resin (based on bisphenol-type chemistry)

wherein R1 and R2 independently represent H, C1-C4 alkyl, or phenyl, and R3 and R4 independently represent H, C1-C4 alkyl, C1-C4 haloalkyl, or phenyl.
(6) 1,2-epoxyalkanes:
(e.g., 1,2-epoxydecane)

(7) 1-alkylimidazoles:

(8) amine salts of nicotinic acid:

wherein R1, R2 and R3 independently represent H, (C1-C18) alkyl or (C1-C18) alkyl substituted with one or more substituents selected from, but not limited to, halogen, hydroxy, alkoxy or alkylthio, provided that the substituents are sterically compatible and the rules of chemical bonding and strain energy are satisfied, or any two of R1, R2 and R3 represent —(CH2)n- where n is an integer from 3-5.
(9) primary, secondary & tertiary amines:

wherein R1, R2 and R3 independently represent H, (C1-C18) alkyl or (C1-C18) alkyl substituted with one or more substituents selected from, but not limited to, halogen, hydroxy, alkoxy or alkylthio, provided that the substituents are sterically compatible and the rules of chemical bonding and strain energy are satisfied, or any two of R1, R2 and R3 represent —(CH2)n— where n is an integer from 3-5.
(10) tertiary amine oxides:

wherein R4, R5 and R6 independently represent (C1-C18) alkyl or (C1-C18) alkyl substituted with one or more substituents selected from, but not limited to, halogen, hydroxy, alkoxy or alkylthio, provided that the substituents are sterically compatible and the rules of chemical bonding and strain energy are satisfied, or any two of R1, R2 and R3 represent —(CH2)n— where n is an integer from 3-5, or
wherein R4 is a straight or branched chain (C1-C18) alkyl or an alkyletherpropyl or alkylamidopropyl of the formula:

wherein R7 is a straight or branched chain (C10-C18) alkyl, and
R5 and R6 independently are straight or branched chain (C1-C18) alkyl or ethoxylates or propoxylates of the formula:

wherein n is an integer from 1 to 20, or mixtures thereof.
(11) tetra-substituted ammonium salts:

wherein R1, R2 and R3 independently represents (C1-C16) alkyl or (C1-C18) alkyl substituted with one or more substituents selected from, but not limited to, halogen, hydroxy, alkoxy or alkylthio, provided that the substituents are sterically compatible and the rules of chemical bonding and strain energy are satisfied, or any two of R1, R2 and R3 represent —(CH2)n— where n is an integer from 3-5, R4 represents ((C1-C16) alkyl or arylalkyl), and X− is selected from, but not limited to, chloride, bromide, or iodide. In some embodiments, N—((C1-C16) alkyl or arylalkyl) tri((C1-C16) alkyl)ammonium salts are those in which R1, R2, R3 and R4 are the same or where R1, R2 and R3 are CH3 and R4 is (C2-C16) alkyl or arylalkyl.
A third set of embodiments includes a formulation, comprising: 2-chloro-6-(trichloromethyl)pyridine, wherein the 2-chloro-6 (trichloromethyl)pyridine is present in the formulation in the range of about 200 to about 400 g/L; at least one polar solvent, selected from the group consisting of: a mixture of N,N-dimethyloctanamide (N,N-dimethylcaprylamide) and N,N-dimethyldecanamide (N,N-dimethylcapramide); and a dibasic ester, wherein the first solvent comprises between about 40 to about 70 weight percent of the formulation; at least one polar solvent miscible corrosion inhibitor, selected from the group consisting of: a liquid epoxy resin; 2,6-dimethylpyridine; epoxidized linseed oil; and nicotinamide; wherein each said polar solvent miscible corrosion inhibitor, comprises about 0.5 to about 2.5 weight percent; and at least one optional solvent selected from the group consisting of: a solvent naphtha, wherein the second solvent comprises about 5.0 to about 20.0 weight percent of the formulation.
A fourth set of embodiments includes a formulation comprising: about 240 to about 350 g/L of 2-chloro-6-(trichloromethyl)pyridine; about 40 to about 60 weight percent of a mixture of N,N-dimethyloctanamide (N,N-dimethylcaprylamide) and N,N-dimethyldecanamide (N,N-dimethylcapramide); about 0.5 to about 1.5 weight percent of liquid epoxy resin and about 0.5 to about 1.5 weight percent 2,6-dimethylpyridine; and about 5 to about 20 weight percent solvent naphtha.
A fifth set of embodiments includes a formulation comprising: about 230 to about 300 g/L of 2-chloro-6-(trichloromethyl)pyridine; about 45 to about 55 weight percent of a mixture of N,N-dimethyloctanamide (N,N-dimethylcaprylamide) and N,N-dimethyldecanamide (N,N-dimethylcapramide); about 0.75 to about 1.4 weight percent of liquid epoxy resin; about 0.5 to about 1.5 weight percent 2,6-dimethylpyridine; and about 10 to about 15 weight percent solvent naphtha.
A sixth set of embodiments includes a formulation comprising: about 240 g/L of 2-chloro-6-(trichloromethyl)pyridine; about 50.0 to about 55 weight percent of a mixture of N,N-dimethyloctanamide (N,N-dimethylcaprylamide) and N,N-dimethyldecanamide (N,N-dimethylcapramide); about 1.0 to about 1.1 weight percent of liquid epoxy resin oil; about 0.5 to about 1.5 weight percent 2,6-dimethylpyridine; and about 11.0 to about 14.0 weight percent solvent naphtha.
A seventh set of embodiments includes a formulation comprising: about 240 g/L of 2-chloro-6-(trichloromethyl)pyridine; about 50.55 weight percent of a mixture of N,N-dimethyloctanamide (N,N-dimethylcaprylamide) and N,N-dimethyldecanamide (N,N-dimethylcapramide); about 1.2 weight percent of liquid epoxy resin oil; about 0.5 to about 1.5 weight percent 2,6-dimethylpyridine; and about 12.64 weight percent solvent naphtha.
An eighth set of embodiments includes a formulation comprising: about 200 to about 400 g/L of 2-chloro-6-(trichloromethyl)pyridine; about 20 to about 50 weight percent of a dibasic ester; about 0.5 to about 2.5 weight percent of epoxidized linseed oil; about 0.5 to about 2.5 weight percent nicotinamide; and about 20.0 to about 50.0 weight percent cyclohexanone.
A ninth set of embodiments includes a formulation comprising: about 240 g/L to about 350 g/L of 2-chloro-6-(trichloromethyl)pyridine; about 45 to about 55 weight percent of a dibasic ester; about 1.0 to about 2.0 weight percent of epoxidized linseed oil; and about 0.8 weight percent nicotinamide; and about 11.0 to about 14.0 weight percent cyclohexanone.
A tenth set of embodiments includes a formulation comprising: about 240 g/L of 2-chloro-6-(trichloromethyl)pyridine; about 50.47 weight percent of a dibasic ester; about 1.5 weight percent of epoxidized linseed oil; about 0.8 weight percent nicotinamide; and about 12.62 weight percent cyclohexanone.
A twelfth set of embodiments includes a formulation, comprising: about 200 to about 400 g/L of 2-chloro-6-(trichloromethyl)pyridine; about 40 to about 60 weight percent of a dibasic ester; about 0.5 to about 2.5 weight percent of epoxidized linseed oil; and about 0.4 to about 1.5 weight percent nicotinamide.
A thirteenth set of embodiments include the twelfth embodiment: about 240 g/L of 2-chloro-6-(trichloromethyl)pyridine; about 63.08 weight percent of a dibasic ester; about 1.5 weight percent of epoxidized linseed oil; and about 0.6 to about 1.0 weight percent nicotinamide.
A fourteenth set of embodiments include a formulation, comprising: about 240 g/L of 2-chloro-6-(trichloromethyl)pyridine; about 63.08 weight percent of a dibasic ester; about 1.5 weight percent of epoxidized linseed oil; and about 0.8 weight percent nicotinamide.
A fifteenth set of embodiments includes a formulation, comprising: about 200 to about 400 g/L of 2-chloro-6-(trichloromethyl)pyridine; about 40 to about 70 weight percent of triethyl phosphate; about 0.5 to about 2.5 weight percent of epoxidized linseed oil; and about 0.5 to about 2.5 weight percent of methyl nicotinate.
A sixteenth set of embodiments includes a formulation, comprising: about 200 to about 400 g/L of 2-chloro-6-(trichloromethyl)pyridine; about 40 to about 70 weight percent of methoxybenzene; about 0.5 to about 2.5 weight percent of nicotinamide; and about 0.5 to about 2.5 weight percent of 2-amino-2-methyl-1-propanol.
A seventeenth set of embodiments including at least one of the formulations according to any of the first through the sixteenth set of embodiments and at least additional agricultural ingredient selected from the group consisting of: herbicides, insecticides, mitocides, fungicides, and fertilizers.
An eighteenth set of embodiments including any of the formulations according to the seventeenth set of embodiments, wherein the agricultural ingredient is a fertilizer.
A nineteenth set of embodiments including any of the formulation according to the eighteenth set of embodiments, wherein the fertilizer includes nitrogen.
A twentieth set of embodiments including methods for treating soil, comprising the steps of: applying at least one of the formulations according to the first through the nineteenth set embodiments to at least one area selected from the area consisting of: the surface of a portion of soil, beneath the surface of a portion of soil, a portion of a plant, and a portion of a surface adjacent to a plant.
A twenty-first set of embodiments including any of the methods according to the twentieth set of embodiments, wherein the applying step includes injecting at least one of the formulations into a portion of soil.